Fetal alcohol syndrome, (FAS) is the leading known cause of mental retardation today and currently represents an enormous problem for our society. The central question addressed by this proposal is whether moderate alcohol exposure constitutes a danger to the developing offspring. To address this issue, we propose to assess the behavior and physiology in 50 monkeys from four conditions: 1) mothers consumed moderate level alcohol daily throughout pregnancy 2) mothers experienced psychological stress; 3) mothers consumed moderate level alcohol and experienced psychological stress; and 4) mothers consumed sucrose (controls) (Schneider et al., 1997). The specific aims are as follows: 1) to characterize dopamine D2 receptor densities in striata of offspring using in vivo PET imaging techniques 2) to characterize dopamine synthesis in these same cohorts, also using PET imaging, and to uncouple presynaptic synthesis of dopamine from postsynaptic receptor binding availability; 3) to evaluate these monkeys with a standard battery of widely accepted tests and measurements, which index cognitive functioning and behavior; and 4) to determine the effects of a dopamine agonist, methylphenidate, on behavior and cognitive performance in this cohort of monkeys. Our primate model has allowed control of the exact timing and level of alcohol exposure to the fetus and the separation of the effects of alcohol from other life-style factors, such as psychological stress The proposed studies provide a unique and unprecedented opportunity not only to better understand the underlying neurobiology of fetal alcohol effects, but also to discover potential in vivo diagnostic markers for detecting fetal alcohol- induced brain damage. Increasing our understanding of the association between behavior, cognition, and molecular mechanisms of neuronal function in fetal alcohol-exposed primates could aid in early identification and appropriate treatment of children with prenatal alcohol exposure.